Other Identifiable Intangible Assets (Schedule of Finite-Lived Intangible Assets by Major Class) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross	$ 323,281,000	$ 308,412,000
Accumulated Amortization	(151,697,000)	(144,047,000)
Net	171,584,000	164,365,000
Amortization expense for finite-lived intangible assets	28,800,000	28,300,000	19,700,000
Finite-lived intangible assets, reclassification related to assets of discontinued operations		2,600,000
Customer lists [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	286,164,000	276,112,000
Accumulated Amortization	(137,782,000)	(132,109,000)
Net	148,382,000	144,003,000
Noncompete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	9,264,000	7,898,000
Accumulated Amortization	(5,438,000)	(6,231,000)
Net	3,826,000	1,667,000
Trade names and licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	27,853,000	24,402,000
Accumulated Amortization	(8,477,000)	(5,707,000)
Net	$ 19,376,000	$ 18,695,000